1. Field of the Invention
This invention relates generally to extension poles with a cable connected between a pole handle end and an opposite pole accessory end to actuate an accessory by action of a trigger lever on the handle end and, more specifically, to such extension poles adjustable in length.
2. Prior Art
It has long been recognized that extending a user""s reach through an extension pole is advantageous. A paint roller mounted on a pole allows one to work beyond one""s natural reach. A pruner on an extension pole allows one to access tree tops otherwise difficult to reach. Painters mount a spray gun on an extension pole also to work beyond one""s natural reach. For accessories such as pruners and fluid sprayers that require an actuating movement, that is, to pull the trigger of the gun, a cable or the like is connected between the pole accessory end and the pole handle end. Movement of a trigger on the handle end is then communicated to the trigger on the spray gun.
Just as it is advantageous to extend one""s reach with an extension pole, it is also advantageous to have available a pole of a preferred length suitable to an application or to changing requirements of an application. Thus, rather than have a number of poles of various lengths requiring the remounting of the accessory between poles, it would be advantageous to have a pole adjustable in length. However, the difficulty introduced is maintaining the operation of the cable between the pole handle end and the pole accessory end to actuate the accessory with action of the pole trigger.
Clearly, one solution is to simply run the cable between a fixed attachment on the pole accessory end and a releasable attachment on the handle end. In which case, a user releases the attachment, such as unscrewing a butterfly screw or similar attachment, adjusting the pole length, perhaps between telescoping members, and reattaching the cable pulled taut along the pole. Though functional, this requires a length-sensitive adjustment of the actuating cable that correctly positions the accessory, such as a fluid spray trigger, with the pole trigger. A misadjustnent, which would tend to be common, would reduce the operational effect of the cable between the handle trigger and the accessory trigger. It would also be a time-demanding bother that would make the pole length adjustment less advantageous to a workman with a premium on his time. A better solution would be to have an extension pole with an adjustment mechanism internal the pole that automatically achieves an operative adjustment of the cable as the pole is adjusted in length, quick and transparent to the user, requiring no additional movement beyond the length adjustment of the pole.
The primary object of the present invention then is to provide an extension pole having an accessory-actuating cable with a length adjustment that automatically adapts the operative length of the cable in concert with the adjustment in length of the pole without separate action by a user. This object is achieved in a pole with telescoping tubular members for pole length adjustment and a cable running between a pole accessory end where an accessory such as a sprayer or a pruner is mounted and a pole handle end where a pole trigger lever is located. When the cable is connected between the trigger lever and the accessory, movement of the trigger is communicated to the accessory through the cable to actuate the accessory.
The cable within the telescoping members comprises two length components, a first cable component running from the pole accessory end toward the pole handle end and a second cable component running from the trigger lever on the pole handle end toward the pole accessory end and overlapping the first cable component. A grasping mechanism is secured in the handle end tubular member with the second cable component connected between the trigger lever and the grasping mechanism such that when the trigger lever is pulled, the grasping mechanism securely engages the first cable component, establishing the cable operative length. Further movement of the trigger lever continues to pull the second component, which then also pulls the second component connected to the accessory. When the trigger lever is released, the grasping mechanism likewise releases from the first component allowing it to slide freely within the grasping mechanism. Thus, when the trigger lever is not pulled, the pole tubular members and cable are free to adjust to any preferred length, movement of the accessory end telescoping relative to the handle end tubular member also moving the first cable component through the grasping mechanism in the handle end tubular member automatically adjusting the operative length of the cable. The two tubular members are then releasably locked together at a preferred length.
Typically, the first cable component comprises a rod with a surface matching the grasping mechanism that enhances a secure engagement of the grasping mechanism with the rod, such as a rack or a notched or threaded rod passing through the grasping mechanism. A more flexible cable typically extends from a rod end out of the accessory end tubular member to an accessory mounted on the pole. The second cable component typically comprises any form of operative line connected between the grasping member and the trigger lever.
The grasping member comprises a latch pivotably mounted transversely in the first tubular member with a hole through which the threaded rod passes. The second cable component is connected to a latch end opposite its pivoting end such that the trigger lever movement pivots the latch. As the latch rotates, it contacts the threaded rod passing through its hole. The hole includes upper and lower beveled surfaces with a plurality of teeth matching the threads of the threaded rod. The beveled surfaces are angled such that when the latch is rotated by the second cable component, they are parallel with the threaded rod, and the teeth engage the threads of the threaded rod, effectively grasping the threaded rod.